22 gallons of bleach and I can't get my chlorine above 5

[cscannon]

Thanks for your help. I had absolutely NO idea that chlorine would disappear so quickly without CYA. Prior to this year, we've always had a cover so I've never had this problem. This year we replaced it and after they took our old one off, they found that the new one wasn't the right size. So now we have nothing.

I am using a Taylor DPD test kit. When I first opened my pool a week ago my pH was 8.0. (I wasn't very faithful about testing it during the winter.) I added enough muriatic acid to bring the pH down to 7.3. A couple of days later I started adding the chlorine. As I did so the pH was going back up and is currently at 7.8. I ignored the high pH thinking that as soon as I was done with the shock I'd be adding CYA which I figured would be lowering the pH. Then I could add whatever muriatic acid was needed after that. TC doesn't seem to be any higher than FC.


Thanks,

Steve

[Watermom]

If your TC is equal to your FC that is what you want because it means that your CC is zero, which is the goal. Until you have an adequate amount of cya in there, it is usually necessary to add bleach morning and evening. (and in some cases, even in the afternoon.)

[cscannon]

What is the relationship between pH and chlorine?

Steve

[chem geek]

What is the relationship between pH and chlorine?

Steve, I don't understand the question. Do you mean if there is a change in chlorine effectiveness with pH? There is, but not as much as those in the industry claim because CYA in the water minimizes this effect so I wouldn't worry much about that.

Do you mean will pH affect the rate of chlorine loss? The answer is yes, to some extent, because higher pH means more of the form of chlorine that breaks down faster in sunlight compared to the form that dominates at lower pH. However, with a lot of CYA in the water, this effect is secondary -- it's mostly seen when there is little CYA in the water such that a combination of no CYA and high pH results in quite rapid loss of chlorine in sunlight.

[cscannon]

My question was in response to CarlD who commented, "What is your pH level? That, too affects chlorine." You've answered that question, thanks.

[CarlD]

That's the other side of the coin. Chem_Geek is explaining how too high pH can reduce chlorine's effectiveness.

However, what I was referring to is that when chlorine levels are very high, pH can appear higher than it really is. Chem_Geek's gone into a thorough explanation of this in other threads. That's why chlorine neutralizer is needed then prior to the pH test.

[cscannon]

Got it thanks!